Table 2.

Sample size requirements for clinical trials with a type 1 error rate of 5% and 20% power to detect a 30% decrease in albuminuria

Number of Urine Samples at Each VisitEstimates of Required Sample Sizes
AVOIDVITALRADAR (0.75 mg/d)RADAR (1.25 mg/d)
Baseline and end of treatment
 1288362202208
 2278356200206
 3282352198204
Baseline and all follow-up visits
 194764040
 280623232
 376583030
  • SEMs (SD) for sample size calculations are derived from our models to assessing the treatment effect between baseline and end of treatment; and from baseline considering all follow-up measurements (five follow-up visits were scheduled in the AVOID trial, whereas six follow-up visits were scheduled in the VITAL and RADAR trials).